THE SEA-SPIDER. 



439 



In the accompanying illustration of the STENORHYNCHUS may be seen one example of the 

 first family of these animals, being a group of Crustaceans distinguished chiefly by the singular 

 form of the carapax or upper shell, which is wide and abrupt at the base, but is prolonged in 

 front, so as to form a long and pointed beak. In all these creatures the legs are long in com- 

 parison to the body, but in the LEPTO PODIA they are of such inordinate length, as to remind 

 the observer of the round-bodied, long-legged harvest spider, which scuttles over the ground 

 so rapidly when disturbed. On account of this great length of limb and small size of body, 

 these crabs are often called Sea-spiders. The eyes of the Leptopodia are rather large, and not 

 retractile. It may here be mentioned that the eyes of Crustacea bear some resemblance to 

 those of insects, being compound organs, with a large number of facets, some square and some 

 hexagonal. The eyes of the common shore crab or the shrimp afford excellent examples 

 of this structure. It is a native of the West Indies. 



8EA.-SPlDER.-Stmortiynctiua longlrostrit. 



In the Stenorhynchus, the projecting beak is proportionately shorter than in the preceding 

 genus, is cleft at the tips, and very sharp. The fore-limbs, which are furnished with large 

 claws, are stout and strong. 



As the shelly armor of the Crustaceans is, in most cases, so hard, strong, and unyielding, 

 the mode of growth might be considered a problem not very easy of solution. For with the 

 Crustaceans the growth continues during nearly the whole of life, or at all events for several 

 years after they have passed through the various changes to which they are subjected in their 

 imperfect stages of existence. Their increase of size and weight is marvellously rapid, and 

 how it can be accomplished without subjecting the Crustaceans to the lot of the starveling 

 mouse, who crawled into a jar of corn, but could not crawl out again after feasting on its 

 contents, seems to partake of the character of an animated puzzle. 



The answer to the problem is simply that the creature sheds its armor annually, expands 

 rapidly while yet covered only by a soft skin, and is soon protected by a freshly -deposited 

 coat of shelly substance. Even this answer contains a second problem little less difficult than 



